This proposal will test ability of autonomous parvo virus vectors (APVs), a novel class of viral vector that we have developed, to deliver genes into cell types relevant for gene therapy in the skin. Efficient gene delivery to keratinocytes has proven difficult and there is an urgent need to investigate novel viral vectors for transduction of skin cells. APVs meet the criteria of "a high degree of innovation and novelty" in relation to their potential impact on treatment of skin diseases, offering significant advantages over other viral vectors. We shall characterize APV transduction of keratinocytes, fibroblasts and endothelial cells, as potential targets for gene therapy in the epidermis, dermis and skin microvasculature. Parvo viruses are small, structurally simple, single strand DNA viruses classified as either autonomous or helper virus dependent (adeno-associated virus, AAV). AAV has attracted much interest as a vector for gene therapy whereas APVs have received little attention in this regard from other groups. We have shown that the rodent autonomous parvo virus, LuIII, can be used for gene transfer and that, although initially expected, to confer transient expression, LuIII vectors can express a transgene persistently (and therefore may have potential for applications requiring sustained expression). Furthermore, our recent finding of efficient transduction of human primary keratinocytes offers a promising route for such applications, via skin ,grafts. Although the mechanism of persistent expression from APVs is not yet understood it has been shown that autonomous parvo virus integration can occur in a model system. Advantages of APV vectors over AAV include the ability to pseudotype these vectors with alternative capsids, and the fact that a helper such as adenovirus is not required for APV vector production. The goals of this proposal are to characterize APV vectors with regard to target cell tropism, duration of transgene expression and possible integration, in cell types relevant for gene therapy of skin diseases.